Shock struts such as those commonly used to form the front forks of motorcycles each usually include a pair of telescoping cylinders with a mechanical spring connected between them either internally or externally to assure extension thereof when excessive forces are not being applied thereacross. Each strut also employs a quantity of fluid such as hydraulic fluid which is forced through narrow passageways within the strut to provide dampening when the two cylinders are moved with respect to each other. The upper surface of the fluid is used as a piston to compress gaseous medium which is usually air trapped in the upper portion of the top telescoping cylinder attached to the triple clamp of the motorcycle. This air spring of course has a variable spring rate that depends upon the deflection of the shock strut. In some instances the gaseous medium is pressurized and the mechanical spring is eliminated.
Unfortunately, because of the rough abuse to which motorcycles and their suspension are subjected, especially when such motorcycles are used in races across desolate areas or in the sport of moto-cross where the course is intentionally made hazardous and rough, the combined mechanical spring and/or air spring must be very stiff since otherwise hard bumps may completely compress them causing the strut to "bottom out" and transmit overloads into the motorcycle frame. This stiffness makes the motorcycle extremely uncomfortable to ride when on relatively smooth terrain since a stiff strut transmits much more vibration and shock to the motorcycle and the motorcyclist than a soft one. Therefore, if an enthusiast buys a motorcycle suitable for off the road racing, he must either buy two sets of shock struts and change them depending on the intended use to live with an extremely rough, jarring and uncomfortable ride when the motorcycle is being used on fairly smooth terrain or pavement. Suitable means have been desired to modify the conventional shock strut so that it is smooth riding on normal terrain and yet can withstand the extreme shocks created when traveling over rough terrain.